METHOD AND APPARATUS FOR BLOWING DRYING GAS IN A PAPER MACHINE

摘要

A method of blowing drying gas against a paper web, and an impingement dryer of a paper machine. Drying gas is blown with an impingement dryer (1) comprising several profiling chambers (19) in the cross-direction of a paper machine (14), the cross-profile of the paper web (11) being controlled with the drying gas blown from the profiling chambers. Each profiling chamber (19) blows drying gas to its own effect range. The impingement dryer further comprises a return air chamber (4) and return air ducts (10) such that drying gas blown against the paper web (11) from the profiling chambers (19) is returned into the return air chamber (4) through the return air ducts (10) in such a way that some of the effect of the drying gas blown from the profiling chamber (19) is at least partly prevented from reaching the effective area of the adjacent profiling chamber (19).